1. Field of the Invention
The invention relates generally to storage device connections and more specifically relates to structures to provide a wireless connection between a disk drive or other storage device and an external device such as a controlling host, storage subsystem, or storage subsystem controller.
2. Related Patents
This patent is related to commonly owned patent application serial number 10/838,725 filed on 4 May 2004 (herewith) and entitled WIRELESS STORAGE ENTERPRISE CONNECTIVITY which is hereby incorporated by reference.
3. Discussion of Related Art
It is generally known in the computing storage arts that a storage device utilizes electronic signals to exchange information between the storage device and an external device controlling the storage device. Examples of such a storage device may include a magnetic or optical disk drives, magnetic or optical tape drives, and other semiconductor-based, volatile, and nonvolatile memory components (such as flash memory devices or so-called “RAM-disks”). Examples of an external device for controlling a storage device may include a host computing system, a host adapter within such a host system, a storage subsystem, a storage controller within such a storage subsystem, or any other controlling device coupled to the storage device.
Typically, the signals exchanged include power signals to provide electrical power for operating the storage device and information signals (command, status and data signals) used for controlling operation of the storage device and for exchanging data to be stored in and read from the storage device. Typically, an electrical power wiring harness provides a hard-wired connection to apply power signals from an external source or device to the storage device for purposes of supplying power to the storage device. Most frequently, the electrical power signals so applied are direct current (“DC”) electrical power signals including one or more DC voltage levels used for operating the storage device. In addition, a second signal cable is typically used for exchanging information signals between an external device and the storage device. This second interface cable may utilize any of several well-known interface signal media and protocol standards including, for example, IDE, SCSI, Fibre Channel, serial attached SCSI (“SAS”) and serial AT attachment (“SATA”) signaling standards. Those of ordinary skill in the art will recognize a wide variety of other well known signaling media and protocols used for exchanging information signals and power signals between storage devices and external device used to control the storage device. In particular, some signaling cables and signal paths provide both power and information signals over a common cabling/signal harness. It is not necessary that power and information signals be segregated between two (or more) distinct cable structures.
In a simple, single computing node, hard-wire power and information cable harnesses between the external device (i.e., internal to the computing system) and the storage device provide a relatively simple, inexpensive design that is easily manipulated by a human user or technician. A first cable harness may be used for providing power to one or more storage devices within such a simple, computing node and a separate cable harness may typically be used for coupling information signals within such a host system. However, in larger, more complex storage subsystems that may include tens, hundreds or even thousands of storage devices within one or more storage enclosures, such hard-wired cable interface techniques are both complex and costly. Complex wiring harnesses and backplanes for exchange of signals are typically utilized and impose a significant cost in the overall storage subsystem. Distribution of such power and information signals within complex storage subsystems therefore presents problems in complexity and cost. Although serial attach standards including optical serial attachments somewhat simplify these issues. However, even simplified serial attach cabling remain costly and complex where tens, hundreds or even thousands of storage devices are provided within a large, complex storage subsystem.
It is evident from the above discussion that an ongoing problem persists in simplifying and reducing cost associated with distributing power and information signals between external controlling devices and storage devices in large complex computing and storage enterprises.